Cutting knife for slitting metal foil

ABSTRACT

A rotatable cutting knife for use in a machine for slitting a moving web of metal foil, the cutting knife cooperating with a driven backup knife to slit the foil by a shearing action. The cutting knife has a concave configuration and is supported by a structure affording adjustments of the cutting knife with respect to the backup knife, thereby reducing the overlaping of the knives required to shear a particular foil and minimizing the possibility of the cutting knife overriding the backup knife.

United States Patent Youn [4 1 Mar. 28 1972 [54] CUTTING KNIFE FORSLITTING 852,964 5/1907 Koegel ..83/675 METAL FOIL 1,559,680 11/1925Denne ..83/676 X 2,212,457 8/1940 Schrier... .....83/502 X [72]2,285,846 6/1942 Stocker... ..s3/4s2 [73] Assignee: John DusenberyCompany, Inc., Clifton, 2,571,201 10/1951 Clem ..83/482 NJ. 3,367,2252/1968 Stanford et a1 ..83/501 X Flled: 1970 Primary Examiner-Frank T.Yost [2]] Appl. No.: 32,552 Attorney-Rudolph J. Jurick [52] us. a483/474, 83/482, 83/502, [57] ABSTRACT 83/503 83/675 83/675 A rotatablecutting knife for use in a machine for slitting a [51] Int; Cl ..B26d1/28 moving web f metal f il the cutting k if cooperating m, a [58]Field of Search ..83/474, 49, 482, 502, 503, driven backup knife to mthe f by a Shearing action The 83/501 676 cutting knife has a concaveconfiguration and is supported by a structure afiording adjustments ofthe cutting knife with [56] References Cied respect to the backup knife,thereby'reducing the overlaping UNITED STATES PATENTS of theknit'esrequired to sheara particular foil and minimizing the possibility of thecutting knife overriding the backup knife. 3,080,784 3/1963 Schneider..83/482 3,185,010 5/ 1965 Printz et a1 9 Claims, 5 Drawing Figures H"""I'IIH "1 mil H n h n 1 Ill 7/ I i Il f 72 I 3e 62 "'"1 |ll 43,- 4| ll, -66

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A ORNE Y 1 CUTTING KNIFE FOR SLITTING METAL FOIL BACKGROUND OF THEINVENTION thereby to shear a web of foil moving between the two knives.

Heretofore, it has been necessary to provide a knife overlap to some0.030 inch in order to provide the shearing action and to prevent thecutting knife from overriding the edge of the backup knife, particularlyin high speed slitting machines. This amount of overlapping of theknives cannot be tolerated in a machine for slitting relatively thinfoil of a soft metal as, for example, soft aluminum foil having athickness of the order of 0.002 inch. The excessive overlapping of theknives produces a curling over of the edges of the slit foil whichresults not only in uneven wound rolls but also, limits the applicationsfor which the slit foil may be used. Furthermore, in present slittingmachines, a plurality of cutting knives are supported in operativeposition with respect to associated backup knives by a common knife beamwhich is adjustable in one direction to permit the initial feeding ofthe foil between the knives and in the opposite direction to set thecutting knives in overlapping relationship to the edges of the backupknives. Such arrangement requires grinding the cutting knives to aprecise diameter. Also, an adjustably mounted knife beam is subject tovibration during machine operation, which requires a greater thannecessary amount of knife overlap to assure a positive shearing actionand to prevent the cutting knives from riding up onto the peripheralsurfaces of the associated backup knives.

Cutting knives constructed and arranged in accordance with thisinvention overcome the shortcomings of existing arrangements. Thecutting knives are supported on the knife beam by individual structuresand the cutting knives are individually adjustable with respect to theassociated backup knives, thereby permitting a close control of knifeoverlap. Also, the cutting knives are mounted on individual backingdiscs in a manner which substantially eliminates the possibility of acutting knife overriding the backup knife even though the knife overlapis set to a minimum value.

ABSTRACT OF THE INVENTION A cutting knife is stressed into a bowedcondition by securing the knife in face contact with a tapered surfaceformed on a rotatable backing disc. The backing disc and its supportingbearings are pivotally secured to a structure which is attachable to aknife beam, said structure including means for the adjustment of theknife in two planes, thereby to set the knife in proper operatingposition with respect to an associate backup knife. The structure alsocarries means for displacing the cutting knife relative to the backupknife for the purpose of threading a metal foil between the two knivesand thereafter returning the knife to its initially establishedoperative position.

An object of this invention is the provision of an improved cuttingknife particularly adapted for slitting thin metal foil.

An object of this invention is the provision of foil slitting apparatusof the class having a cutting knife cooperating with a backup knife,which apparatus includes means for setting and maintaining a minimumoverlapping of the two knives required to slit metal foil of a giventhickness.

An object of this invention is the provision of a cutting knife forslitting metal foil, which cutting knife is secured in face engagementwith a tapered surface formed on a rotatably mounted backing disc.

An object of this invention is the provision of a cutting knife forslitting metal foil, said knife being freely rotatable and supported forpivotal movement by a structure which is attachable to the knife beam ofa slitting machine, said structure including means affording adjustmentof the cutting knife in two planes.

The above-stated and other objects and advantages of the invention willbecome apparent from the following description when taken with theaccompanying drawings. It will be understood however, that the drawingsare for purposes of illustration and are not to be construed as definingthe scope or limits of the invention, reference being had for the latterpurpose to the claims appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings wherein like referencecharacters denote like parts in the several views:

FIG. ii is a top plan view of a cutting knife assembly made inaccordance with this invention, the upper bearing housing being brokenaway to show the bearings and the shah to which the knife is secured;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a right side elevational view with the lower bearing housingbroken away to show the pivotal mounting of the knife;

FIG. 4 is a front end elevational view; and

FIG. 5 is a fragmentary, horizontal cross-sectional view drawn to anenlarged scale and showing the cutting knife in operative position withrespect to the backup knife.

DESCRIPTION OF PREFERRED EMBODIMENTS Reference now is made particularlyto FIGS. 2 and 3 showing the dove-tail mounting bar 10 by means of whichthe knife assembly is attachable to the fixed knife beam 111 carried bya cross member 112 of a slitting machine. A clamp 13, pivotally attachedto the bar 10, by a pin 14, serves as a means for securing such bar tothe knife beam upon manual operation of the hand screw 15, said screwbeing threaded through a hole provided in a block 116 which is bolted tothe end of the bar 10. The circular knife ll7, having a thickness of0.0l0-0.020 inch, and a metalbacking disc 18 are clamped between aninner flange 19, formed integrally with the shaft 20, and an outerclamping washer 21 by a socket screw 22, FIG. 1. This as sembly will beunderstood by reference to the enlarged, fragmentary sectional view ofFIG. 5, wherein the knife 17 is shown in operative position with respectto a power-driven backup knife 25 having a tapered edge 26. It will benoted that the backing disc 18 has an inwardly tapered marginal faceportion presented to the cutting knife and that the clamping washer 21retains the marginal face portion of the cutting knife against the discedge 24 and offset at an angle with respect to the median plane of thebacking disc, thereby prestressing the cutting knife. A thin, flexibleknife normally cannot be manufactured or mounted economically to runwith a sidewise wobble of less than 0.005 inch. However, the relativelythick, rigid backing disc can be made and mounted so that the sidewisewobble is less than 0.0002 inch. In this arrangement, a commerciallymanufactured knife blade is forced to run with a minimum side wobble anda small amount of prestress. Therefore, the knife will operate incontinuous contact with the edge of the backup knife with minimumoverlap and with minimum potential of overriding such edge. The amountof knife overlap, and the initial lateral pressure applied to thecutting knife are individually adjustable by means which will bedescribed herein below. The peripheral surface of the backing disc is isprovided with a circular groove accommodating a ring 27 made of rubberor other resilient material, which n'ng serves to minimize the tendencyof the foil to wrinkle at the slitting station and to rotate the cuttingknife at a peripheral speed corresponding to the linear speed of thefoil. The shaft 20 passes through an opening formed in the end of acylindrical housing 28.

Referring now to FIG. l, the described cylindrical housing 28 carries apair of spaced ball bearings having their outer races press-fitted intoappropriate circular channels formed in the inner wall of the housing.The shaft 20 passes through the bearings and is clamped to the innerraces of the bearings by means of an axial bushing 3i, end plate 32 andscrew 33, the

latter being threaded into a hole formed in the end of the shaft 20. Thenormally open end of this housing is closed by a plate 34 secured inposition by the screws 36. It will be apparent that the cutting knife 17is freely rotatable about the bearing axis.

The cylindrical housing 28 (FIGS. 1 and 2) forms part of a structurewhich includes a second cylindrical housing 37 and a downwardlyextending lever 38, the housing 37 having a normally open end closed bythe plate 39. The end portion of the lever 38 is positioned to strikeagainst the end of an adjustable stop screw 40 having a threaded shankpassing through a threaded hole formed in a forwardly extending post 41(as viewed in FIG. 1), which post is formed integrally with a transverseblock 42 secured in fixed position to a slide plate 43. A heavy spring44 is compressed between the post 41 and the knurled head of the screw40, thereby to retain the screw in a set position. The cylindricalhousing 37, oriented at a right angle to the cylindrical housing 28,carries a pair of spaced ball bearings retained in place in a mannersimilar to the ball bearings carried by the cylindrical housing 28. Thebroken away portion of FIG. 3 shows one of the bearings 45 carried bythe cylindrical housing 37. The inner races of the two bearings,disposed in the housing 37, are mechanically coupled to a shaft 47 by abushing and end plate arrangement similar to that shown in the housing28 of FIG. 1. An end of the shaft 47 is rigidly secured to the slideplate 43, it now being apparent that the cutting knife is freelyrotatable about the axis of the shaft 47.

Referring to FIG. 3, the facing surfaces of the slide plate 43 and thedove-tailed mounting plate have aligned, V-shaped channels formedtherein, which channels accommodate a spacing rod 48 secured in placewith respect to the slide plate by a roll pin 49. A washer 50 is securedto the end of the spacing rod by means ofa cap screw 51, and an alignedcap screw 52 is carried by an end plate 53 secured to the mounting plate10 by the screws 54 (see also FIG. 4). A spring 55 is compressed betweenthe washer 50 and the end plate 54. Thus, the spring biases the spacingrod and the slide plate 43 in the direction of the calibrated,differential screw 56. The outer, reduced-diameter shank portion 57, ofthe screw 56, is provided with a relatively coarse thread and passesinto a correspondingly threaded hole formed in an end block 58 which issecured to the end of the slide plate 43, whereas the enlarged diametershank portion 59 is provided with a fine thread and passes through acorrespondingly threaded hole formed in the end block 16 which issecured to the end of the mounting plate 10. As an example, the screwshank portion 59 may be provided with 50 threads per inch, whereby onerevolution of the screw results in a 0.005 inch linear displacement ofslide plate 43 relative to the mounting plate 10. Such displacement alsois imparted to the cutting knife which is pivotally secured to the slideplate by the shaft 47.

As shown in FIG. 2, the slide plate 43 is clampingly secured to themounting plate 10 by a threaded stud 61 threaded into a hole provided inthe mounting plate and having a flat central portion slidable in anelongated slot 62 formed in the slide plate. An assembly of flat washersand spring washers is positioned between the slide plate and a nut 63which is threaded on the stud. The spacing rod 48, visible in FIG. 3,lies to the right of the bolt 61 as viewed in the top plan view of FIG.I. A set screw 65, FIG. 1, is threaded through a hole formed in theslide plate 43 and has an end engaging the underlying surface of themounting plate. This set screw provides a means for setting the twospaced plates 43 and 10in parallel planes, after which the nut 63, FIG.2, is tightened on the stud 61 to provide a desired clamping pressurebetween each of these plates and the spacing rod. The lineardisplacement of the slide plate relative to the mounting plate, uponrotation of the differential screw 56, is limited by the axial extent ofthe elongated slot 62 formed in the slide plate.

As best seen by reference to FIGS. 2 and 3, an air cylinder 66 has oneend secured to a block 67 and the other end passing through a clearanceopening formed in the transverse block 42, said blocks being secured tothe slide plate 43. The air cylinder is secured to the block 67 byscrews, not shown. The piston 68, of the air cylinder, is connected toan L-shaped bracket 69 and a pin 72 pivotally couples the bracket to anarm 71 welded to the cylindrical housing 37. Air under pressure isapplied to the air cylinder through a flexible hose connected to thecylinder at the end opposite the piston. In the absence of air pressureapplied to the cylinder, a spring, disposed in the cylinder, biases thepiston to the retracted position, causing the cylindrical housing 37,the lever 38 and the cutting knife to rotate about the shaft 47 seen inFIG. 3. This rotation corresponds to a clockwise rotation of thedescribed assembly as viewed in FIG. 1, the axis of rotation beingidentified by the letter 'a' (FIG. 1). The extent of such clockwiserotation is limited by the backing disc 18 striking the L-shaped bracket69, in which position the cutting knife is spaced from the backup knifeso that a metal foil can be passed between the knives prior to placingthe slitting machine in operation. When air pressure is applied to theair cylinder, the piston is driven outwardly of the cylinder and thecutting knife is moved to the position shown in FIG. 1, thecounterclockwise rotation of the cutting knife about the axis a beinglimited by the lever 38 striking the end of the stop screw 40. Byadjusting the screw 40, the lateral pressure between the cutting knifeand the cooperating edge of the backup knife (FIG. 5) can be set to adesired magnitude.

In setting up the machine for slitting foil of a given thickness, say,0.002 inch, the described assemblage is clampingly secured to the knifebeam 11 (FIG. 2) so that the cutting knife 17 (FIG. 5) is positioned tostrike the peripheral surface of the backup knife 25. The differentialscrew 56 (FIG. 2) is adjusted carefully until the peripheral surface ofthe cutting knife engages the peripheral surface of the backup knife.The assemblage then is unclamped from the knife beam, moved to aposition wherein the cutting knife just clears the edge 26 of the backupknife, after which the assemblage is again clamped to the knife beam.The differential screw 56, FIG. 2, again is adjusted to displace theslide plate 43 0.003 inch in the direction of the cutting knife, therebyestablishing an overlap of 0.003 inch between the cutting knife and thebackup knife. During this portion of the setting-up procedure, the stopscrew 40, FIG. 1 has been threaded through the post 41 so that its endprojects somewhat further from the post. Air under pressure now isapplied to the air cylinder, whereby the lever 38 strikes the end of thescrew 40, in which position the lever will occupy a position displacedclockwise from the illustrated position. The purpose of such preliminarysetting of the screw 40 is to prevent the cutting knife from strikingthe cooperating edge of the backup knife with an excessive force. Now,the screw 40 is backed-off slowly until the cutting knife engages theedge 26, after which the screw is backed-off farther, thereby to apply adesired pressure between the cutting knife and the backup knife. Thedescribed adjustments of the cooperating knives is of particularadvantage in slitting machines having a plurality of such cooperatingknives. The individual adjustment of each cutting knife with respect toits associated backup knife eliminates the requirement from grinding thecutting knives to a precise, equal radius. This feature also permits theclamping of each cutting knife assemblage to a rigid knife beam anchoredin fixed position to the machine frame, thereby eliminating undesirablevariations in the preset overlapping of the knives during machineoperation, which variations occur when the knife beam is mounted for twodirection adjustment on the machine frame. Furthermore, the cuttingknife assembly makes it possible to reduce the amount of knife overlapto that required only to shear the foil while, at the same time,providing the necessary pressure between the cutting knife and theassociated backup knife. The backing disc and the prestressed conditionof the cutting knife prevent the knife from riding up onto theperipheral surface of the backup knife even under high speed machineoperation.

Having now described the invention, what I desire to protect by LettersPatent is set forth in the following claims.

1. An assemblage for use in a foil-slitting machine and comprising,

a. a circular cutting knife,

b. a circular backing disc having a diameter less than that of thecutting knife, one face of the disc consisting of a central surfaceportion parallel to the median plane of the disc and a tapered marginalsurface portion extending inwardly from an edge of the disc,

c. means securing the cutting knife to the backing disc, said meansincluding a clamping member retaining the central portion of the cuttingknife in flush contact with the said central surface portion of thebacking disc and with a marginal face portion of the cutting knife inpressure contact with the said edge of the disc,

d. means mounting the cutting knife and backing disc for free rotationabout a first axis normal to the median plane of the backing disc, and

e. means mounting the cutting knife and backing disc for pivotalmovement about a second axis normal to the said first axis.

2. The invention as recited in claim 1, including a circular grooveformed in the peripheral surface of the backing disc, and a ring ofresilient material carried in the groove and extending radially outwardtherefrom.

3. An assemblage for use in a foil-slitting machine having a knife beam,which assemblage comprises,

a. a mounting plate removably securable to the knife beam,

b. a slideplate carried by the mounting plate,

c. manually operable means for displacing the slide-plate relative tothe mounting plate,

d. a rotatable member carried by the slideplate and rotatable about afirst axis normal to the plane of the slideplate,

e. a backing disc,

f. a circular cutting knife,

g. means securing the backing disc and the cutting knife to a shaft,

h. means carried by said rotatable member and supporting said shaft forrotation about an axis normal to the said first axis and parallel to theplane of the slideplate,

. actuating means mechanically coupled to said rotatable member,actuation of said actuating means rotating the rotatable member aboutits axis, and

j. cooperating stop means carried by the slideplate and the rotatablemember to limit rotation of the latter upon actuation of the actuatingmeans.

4. The invention as recited in claim 3, wherein said actuating means isan air cylinder carried by the slideplate and having a piston coupled tothe said rotatable member, and wherein said cooperating stop meanscomprises a lever carried by the rotatable member and an adjustablescrew carried by the slideplate.

5. The invention as recited in claim 3, wherein the backing discincludes a tapered surface portion extending inwardly nan from an edgeof the disc, and including means retaining the marginal portion of theknife face in pressure contact with the said edge of the disc and offsetwith respect to the median plane of the backing disc.

6. The invention as recited in claim 5, including a circular grooveformed in the peripheral surface of the backing disc, and a ring ofresilient material disposed in said groove and extending beyond theperipheral surface of the backing disc.

7. The invention as recited in claim 3, wherein the manually operablemeans for displacing the slideplate relative to the mounting platecomprises a first block secured to an end of the mounting plate, asecond block secured to the proximate end of the slideplate, and a screwhaving a first threaded portion passing through a threaded hole formedin the said first block and a second threaded portion passing into athreaded hole formed in the said second block, the threaded portions ofthe screw having different threads.

8. in a foil-slitting machine of the class having a circular cuttingknife carried by a knife beam and cooperating with a backup knifecarried by a driven shaft, the improvement comprising,

a. a mounting plate removably secured to the knife beam,

b. a slideplate carried by the mounting plate,

c. manually operable means for displacing the slideplate with respect tothe mounting plate and in a direction substantially normal to the axisof said shaft,

d. a rotatable member carried by the slideplate and rotatable about anaxis normal to the plane of the slideplate,

e. a backing disc having a diameter less than that of the cutting knife,a face of said disc having a tapered surface portion extending inwardlyfrom an edge of the disc,

f. means securing the cutting knife to the backing disc with a marginalface portion of the cutting knife in pressure contact with said edge ofthe disc and offset with respect to the median plane of the backingdisc,

g. means carried by the said rotatable member and mounting the cuttingknife and the backing disc for free rotation about an axis normal tothat of the rotatable member,

h. means normally biasing said rotatable member in one direction tospace the cutting knife from the backup knife,

i. actuating means for rotating said rotatable member in the otherdirection, and

j. adjustable stop means limiting rotation of said rotatable member insaid other direction.

9. The invention as recited in claim 8, wherein the said actuating meanscomprises an air cylinder carried by the slideplate and having a pistonmechanically coupled to said rotatable member, and wherein saidadjustable stop means comprises a lever carried by the rotatable memberand an adjusting screw carried by the slideplate and lying in the pathof travel of the said lever.

1. An assemblage for use in a foil-slitting machine and comprising, a. acircular cutting knife, b. a circular backing disc having a diameterless than that of the cutting knife, one face of the disc consisting ofa central surface portion parallel to the median plane of the disc and atapered marginal surface portion extending inwardly from an edge of thedisc, c. means securing the cutting knife to the backing disc, saidmeans including a clamping member retaining the central portion of thecutting knife in flush contact with the said central surface portion ofthe backing disc and with a marginal face portion of the cutting knifein pressure contact with the said edge of the disc, d. means mountingthe cutting knife and backing disc for free rotation about a first axisnormal to the median plane of the backing disc, and e. means mountingthe cutting knife and backing disc for pivotal movement about a secondaxis normal to the said first axis.
 2. The invention as recited in claim1, including a circular groove formed in the peripheral surface of thebacking disc, and a ring of resilient material carried in the groove andextending radially outward therefrom.
 3. An assemblage for use in afoil-slitting machine having a knife beam, which assemblage comprises,a. a mounting plate removably securable to the knife beam, b. aslideplate carried by the mounting plate, c. manually operable means fordisplacing the slide-plate relative to the mounting plate, d. arotatable member carried by the slideplate and rotatable about a firstaxis normal to the plane of the slideplate, e. a backing disc, f. acircular cutting knife, g. means securing the backing disc and thecutting knife to a shaft, h. means carried by said rotatable member andsupporting said shaft for rotation about an axis normal to the saidfirst axis and parallel to the plane of the slideplate, i. actuatingmeans mechanically coupled to said rotatable member, actuation of saidactuating means rotating the rotatable member about its axis, and j.cooperating stop means carried by the slideplate and the rotatablemember to limit rotation of the latter upon actuation of the actuatingmeans.
 4. The invention as recited in claim 3, wherein said actuatingmeans is an air cylinder carried by the slideplate and having a pistoncoupled to the said rotatable member, and wherein said cooperating stopmeans comprises a lever carried by the rotatable member and anadjustable screw carried by the slideplate.
 5. The invention as recitedin claim 3, wherein the backing disc includes a tapered surface portionextending inwardly from an edge of the disc, and including meansretaining the marginal portion of the knife face in pressure contactwith the said edge of the disc and offset with respect to the medianplane of the backing disc.
 6. The invention as recited in claim 5,including a circular groove formed in the peripheral surface of thebacking disc, and a ring of resilient material disposed in said grooveand extending beyond the peripheral surface of the backing disc.
 7. Theinvention as recited in claim 3, wherein the manually operable means fordisplacing the slideplate relative to the mounting plate comprises afirst block secured to an end of the mounting plate, a second blocksecured to the proximate end of the slideplate, and a screw having afirst threaded portion passing through a threaded hole formed in thesaid first block and a second threaded portion passing into a threadedhole formed in the said second block, the threaded portions of the screwhaving different threads.
 8. In a foil-slitting machine of the classhaving a circular cutting knife carried by a knife beam and cooperatingwith a backup knife carried by a driven shaft, the improvementcomprising, a. a mounting plate removably secured to the knife beam, b.a slideplate carried by the mounting plate, c. manually operable meansfor displacing the slideplate with respect to the mounting plate and ina direction substantially normal to the axis of said shaft, d. arotatable member carried by the slideplate and rotatable about an axisnormal to the plane of the slideplate, e. a backing disc having adiameter less than that of the cutting knife, a face of said disc havinga tapered surface portion extending inwardly from an edge of the disc,f. means securing the cutting knife to the backing disc with a marginalface portion of the cutting knife in pressure contact with said edge ofthe disc and offset with respect to the median plane of the backingdisc, g. means carried by the said rotatable member and mounting thecutting knife and the backing disc for free rotation about an axisnormal to that of the rotatable member, h. means normally biasing saidrotatable member in one direction to space the cutting knife from thebackup knife, i. actuating means for rotating said rotatable member inthe other direction, and j. adjustable stop means limiting rotation ofsaid rotatable member in said other direction.
 9. The invention asrecited in claim 8, wherein the said actuating means comprises an aircylinder carried by the slideplate and having a piston mechanicallycoupled to said rotatable member, and wherein said adjustable stop meanscomprises a lever carried by the rotatable member and an adjusting screwcarried by the slideplate and lying in the path of travel of the saidlever.